P0172 on Cadillac vehicles The engine is running rich on bank 1: too much fuel for the air going in

A model year is listed because the code is named in its own record — a bulletin filed against it, or an owner’s complaint about it — not because every one of these vehicles sets it. Counts are documents in NHTSA’s files, not failure rates.

Bulletins and campaigns Cadillac filed with NHTSA whose summary names P0172. Quote the document number at the service desk — it is a diagnosis the maker has already written down.

• 22-NA-128 Service bulletin
  2024-05-30 · Engine
• This technical bulletin provides a procedure to test the intake manifold for any possible leaks that may cause the customers concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P0172, P026D, P2459, and/or P2A00 Set.
• 22-NA-128 Service bulletin
  2024-08-09 · Engine
• This technical bulletin provides a procedure to test the intake manifold for any possible leaks that may cause the customers concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P0172, P026D, P2459, and/or P2A00 Set.
• PIP5446 Service bulletin
  2016-11-30 · Power Train — Automatic Transmission
• This Preliminary Information communication provides information to the technician about vehicles that have a Harsh Shift 1/2 and 2/3 and Sputter Applying Throttle Between 0 and 30%, Rough idle. Technician may find Diagnostic Trouble Codes P0101, P0171, P0172, P0174, and or P0175. Technician should inspect for cast flashing near the Mass Air Flow sensor as seen below.
• PIP5446A Service bulletin
  2018-01-18 · Back Over Prevention
• This Preliminary Information communication provides information to the technician about vehicles that have a Harsh Shift 1/2 and 2/3 and Sputter Applying Throttle Between 0 and 30%, Rough idle. Technician may find Diagnostic Trouble Codes P0101, P0171, P0172, P0174, and or P0175. Technician should inspect for cast flashing near the Mass Air Flow sensor as seen below.
• 18-NA-246 Service bulletin
  2022-03-11 · Electrical System
• This service bulletin provides repair procedures, depending on model year, to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated with DTC P0172, P06DE and/or P0521 Set.
• PIP6115 Service bulletin
  2026-05-21 · Unknown Or Other
• The document advise technicians after an engine repair involving removal of the camshaft actuators, the vehicle may set p1101 P0172 and or stalls when taken off idle. The technician is instructed to verify the intake and exhaust camshaft actuators are installed onto the correct camshafts.

A stored code names the test that failed, never the part that caused it. The record above is what Cadillac and its owners have filed about it; the code’s page across every make has the whole file.